Epifanovite
Epifanovite is an IMA-recognized mineral species in the phosphate class, with the chemical formula NaCaCu₅(PO₄)₄[AsO₂(OH)₂]·7H₂O.
It crystallizes in the monoclinic crystal system (space group P2_1/m). It is a member of the Andyrobertsite structural group.
Key properties: Mohs hardness 3; specific gravity 3.65; Pale blue streak; Vitreous luster; optically biaxial.
IMA symbol Efv, IMA status: approved, named in 2016.
A secondary low-temperature mineral produced through alteration of primary minerals in a quartz-phosphate mass ~5 m in diameter within greisenized cassiterite-bearing granodiorite.
It is found associated with Copper, arsenolite, tobermorite, slavkovite, libethenite, pseudomalachite, fluorapatite.
The mineral was named to honor Porphiriy Prokopievich Epifanov, Russian geologist, the discoverer of the Këster, Ege-Khaya, and others tin deposits between 1936-1938.